Process and device for producing foundry cores



Aug. 13, 1963 JEAN-JACQUES GERARDIN 3,100,321

PROCESS AND DEVICE FOR PRODUCING FOUNDRY CORES Filed Nov. 20, 1961 5 Sheets-Sheet 1 f 16 16 3 i J 3 6 i3 J 5 3 1963 JEAN-JACQUES GERARDIN 3,100,321

PROCESS AND DEVICE FOR PRODUCING FOUNDRY CORES Filed Nov. 20, 1961 3 Sheets-Sheet 2 DMunhm Tenn-Eg n RARD/N AHormey g- 1963 JEAN-JACQUES GERARDIN 3,100,321

PROCESS AND DEVICE FOR PRODUCING FOUNDRY CORES Filed Nov. 20, 1961 3 Sheets-Sheet 3 ITI'IIV Jm/en 1801- Tanya; GERARD y; QQ/gfitmliuy AH'Orney United States Patent Ofiice 32,100,321 Patented Aug. 13, 1963 3,100,321 PROCESS AND DEVICE FOR PRODUCWG FOUNDRY CORES Jean-Jacques Gerardin, (files-Jean, Pont-a-Mousson,

France, assignor to Compagnie do Pont-a-Mousson, Nancy, Meurthe-et-Moselie, France, a corporation of France Filed Nov. 20, 1961, Ser. No. 153,588 Claims priority, application France Dec. 3, 1960 2 Claims. (CI. 22-10) vided so that its ends project from the latter and can be used when handling the core. According to a known method, in the course of production of the core, the reinforcement which is previously placed in the lower part of the empty core-box rests at its ends on rigid supports on said lower part. The sand or mixture containing said is poured in excess amount, the upper part is pressed onto the lower part of the box, for example by means of a press, and the sand is packed or compressed inside the box in a manner which is not at all uniform. Indeed, the rigid reinforcement which rests at its ends on supports which are also rigid constitutes an obstacle to proper packing of the sand. As a result, the part of the core located behind this obstacle is less compressed than the zone in which the obstacle does not exist. This unequal compression has an adverse eifect on the solidity of the core.

Further, if the reinforcement is insufiiciently rigid, that is, if it is capable of elastically bending under the sand compressing force, it tends to resume its straight shape when it is no longer subjected to this force and is liable to break the core in so resuming its straight shape.

The object of the invention is to eliminate these disadvantages.

The invention provides a process of producing a foundry core provided with at least one reinforcement in which the reinforcement is supported during the filling of the core-box with sand, after which this reinforcement is released from any support during the compression and packing of the core.

Owing to this improved process, during the compression the reinforcement no longer rests on rigid supports, but on the contrary freely rests in the sand so that it follows the movements of the latter and fully transmits thereto the compression force throughout its length without opposing local resistances.

Another object of the invention is to provide a corebox having two parts separated in a horizontal joint plane and improved so as to permit the application of said process. Said core-box comprises supports which are retractable from the reinforcement of the core and are mounted in the lower part of the core-box.

In an embodiment of the invention, the supports for the reinforcement are constituted by elements vertically slidable in the lower part of the core-box.

In another embodiment, the reinforcement supports are constituted by rods horizontally slidable in the lower part of the core-box.

Another object of the invention is to provide a device for producing foundry cores comprising the combination of the aforementioned core-box and means for actuating In the drawings:

FIG. 1 is a longitudinal sectional view of a device according to a first embodiment of the invention, this view corresponding to the device in the state of rest before filling with sand, the upper part of the core-box having been replaced by an extension part;

FIGS. 2 and 3 are respectively cross-sectional and horizontal sectional views along lines 22 and 3-3 respectively of FIG. 1;

FIG. 4 is a sectional view similar to FIG. 1 ofthe device after it has been filled with said or a mixture containing sand;

FIG. 5 is a cross-sectional view taken along line 55 of FIG. 4;

FIG. 6 is a View similar to FIG. 5 after the box has been filled with sand and the extension portion has been removed;

FIG. 7' is a longitudinal sectional view of the device according to the invention in a position for compressing or packing the core between the two parts of the core-box;

FIG. 8 is a sectional view taken along line 8-8 of FIG. 7;

FIG. 9 is a partial longitudinal sectional view of. a modification of. the device shown in FIGS. 1-8;

FIG. 10 is a cross-sectional view taken along line 16- 10 of FIG. 9; I

FIG. 11 is a plan view corresponding to FIG. 9;

FIG. 12 is a partial perspective view of the modification shown in FIG. 9;

FIG. 13 is a plan view of another modification of the device;

FIG. 14 is a sectional view taken along line 14--14 of FIG. 13;

FIG. 15 is a longitudinal sectional view of a second embodiment of the invention, the device being shown in position for filling the core-box;

FIG. 16 is a sectional view taken along line 16-16 of FIG. 15, and a FIG. 17 is a partial sectional view similar to FIG. 15 of the device in position for compressing the core.

In the embodiment shown in FIGS. 1-8 the invention is applied i013. metal core-box A (FIGS. 7 and 8) having two superimposed parts. 1 and 2 interconnected in a substantially horizontal joint plane I.

The lower part 1 fixed to a table B comprises a mould tor impression 3 which is limited in the upward direction on the joint plane I and is extended at its ends in accordance with the invention in such manner as to form two vertical slideways 4 in each of which is slidably mounted a slide 5 of a support for a reinforcement 6. The supports 5 ordinarily rest in the lower position on the bottom of the lower part 1 (FIG. 1) in which they are below the joint plane J. They are raisable to an upper position above the joint plane by two jacks or rams V, for example having a single-acting piston 7 and actuating rods 8 extending through the bottom of the lower part 1. The upper position of the reinforcement 6 is determined by the abutment of the piston 7 against the table B. The rams V are connected by a pipe 9 anda common branch pipe 7 to one of the ways of a three-way tap 11 of which the other two ways are a supply pipe 12 of fluid under pressure and a discharge pipe 13. The upper part 2 of the core-box (FIGS. 7 and 8) comprises in the known manner a mould or impression :15 which is connected to the mould 3 of the lower part 1 in the joint plane J.

The core-box is used in the following way:

Placed on the lower part 1 of the core-box is an upper extension box 16 (FIGS. 1-3) adapted to measure the amount of loose, that is, uncompressed sand which must be provided to constitute the required core. The tap 11 is so turned as to connect the discharge pipe 13 to sand S (FIG. 6).

Before filling with sand, the tap 11 is turned so as to connect the pipes 9 and 10 to thesupplyrpipe 12 (FIGS. 4- and The rods 8 of the pistons 7 then simultaneously raise the twosupports 5- which raise the reinforcement 6 to the upper position shown in FIGS. 4 and 5. It is in this position that the core-box is filled with sand S or a mixture containing foundrysand in tended to constitute the core. The'filling is carried out either manually or by gravity, or by blowing by means of a core blowing machine of known type. The filling is continued up to the upper edge of this box 16, after which the top 11 returned to the position shown in FIG. 1 so as to connect the rams V to the discharge. The pistons 7 and the supports 5 of the reinforcement 6 descend. However, the reinforcement 6 does not de-' scend since it is supported throughout its length by the V The box 16 is then withdrawn (FIG. 6) and is. replaced by the upper part 2 ofthe core-box (FIG. 7) for packing or compressing the core N.

The application of the upper part2 of the core-box 4 supports 5a in the lower position. The core-box is used in the same manner as the previously-described corebox.

In the modification shown in FIGS. 13 and 14, the invention relates to a core-box having a curved reinforcement 6b. In this case, this reinforcement is not only supported at its ends by the supports 5, which are identical to the previously-describedsupports, but it is on the lower part :1 is preferably effected by means of in the box 16 the volume of which sand is reduced.

Owing to the constant level of filling of the sand in the box :16, the packing pressure of the sand is uniformly distributed throughout the length of the mould or impression on each side of the reinforcement 6.

Owing to the fact that the reinforcement 6 is embedded in the sand and removed from any rigid support, it wholly transmits to the portion of sand located in a press whose bolster 17 (FIGS. 7 and 8) moves for eX- Q have a fiat-shaped cross-section.

the lower mould 3 the pressure transmitted to the reinforcement by the portion of sand located in the upper mould 15 of the core-box.

. The core has been completely compressed when the lower part 1 and upper part 2 are in contact in the joint plane I. 'Ihe reinforcement 6 is then substantially centered in the core N and, owing to the fact that the travel of the piston 7 of the rams V is chosen to be gslightly greater than the extent to which the reinforcement 6 is displaced under the effect of the packing of the sand at the end of the sand packing operation, this reinforcement remains, out ofcontact with the supports 5 whose lower position is below the joint plane I (FIGS. 7 and 8). V e I I The upper part 2 of the corebox is removed after which is taken hold ofby the ends of the reinforcement 6, is withdrawn.

Owing to the invention, the core N'is compressed in a uniform manner and this imparts thereto strength, elasticity and uniform permeability to gases. Further, the reinforcement 6 which moves freely with the sand is in no way deformed. It therefore remains stationary within the core after compression of the latter so that there is no danger of the core breaking.

In. the modification shown in FIGS. 9-12, the supports 5 of the first embodiment are replaced by sup- .ponts 5a which have a U-shaped cross-section, areprovided at their lower part with guide pins 18 and are mounted 1 outside the core-box. To this end, the end walls of the lower part of the core box are recessed at 19. Each recess is limited in the downward direction by'a horizontal ledge 20 which constitutes a shoulder. The supports 5a abut this ledge 20* by their upper horizont-al flange in the lower position and by their lower flange in the upper position. These supports are 'actuated in the above-described manner by the rams V. The reinforcement 6 rests on the upper flanges of the the press holster 17 has been raised. Then the core N,

is the rod of the piston 7b of the jack or ram V1, this rod being sufiiciently upwardly extended to pass through the lower pant 1b of thecore-box and support the reinforcement 6b. The ram V1 is connected to the supply pipe 9 in the same way as the rams V disposed under the ends of the reinforcement 6b so as to actuate the supports 5. The three rams therefore operate simultaneously in the manner described in respect of the first embodiment.

In another embodiment shown in FIGS. 15-17, the

supports for the reinforcement 6 are horizontally movable instead of being vertically movable.-

The lower part 1c of the core-box is provided at its ends with apertured elements 21 on which are fixed guide bushings 22. Horizontally slidable in the latter are rods 50 extending through the elements 21. .These rods act as supports for the ends of the reinforcement 6 and Bach rod comprises a flange 23 constituting an abutment engageable with the bushing 22 and a push button 24 which also forms an abutment engageable with the bushing 22 and acts as a support for a spring 25 compressed in a housing formed in this bushing. Each rod 5c further comprises a locking recess 26 with which co-operates a vertical locking pin 27 extending through the bushing 22 and rigid with the piston 28 of a jack or rain V2. There are two rams V2 corresponding to the two ends of the reinforcement 6.: When these rams are-under pressure the locking pins 26 lock the rods 5c in the position in which they support the reinforcement 6 (springs 25 compressed) as can be seen in FIG. 15. When the rams V2 are connected to the discharge (FIG. 17) the pins 27 descend and release the rods 5a which are withdrawn outwardly by the expansion of the released springs 25.

By means of this device, the core-box is used in the same manner as that described hereinbefore. In their state of rest, the rods 50 are ordinarily outwardly withdrawn (FIG. 17), the rams V2 are put under pressure so as to tend to raise the looking pins 27'. The push buttons 24 are depressed manually and the rods 50 are retained in their operative position by the pins 27 which engage the recesses 26. The reinforcement 6 is then placed on the rods 50 and the extension box1g6e is placed on the lower part 10 of the core-box. After filling with sand, the rams V2 are connected to the discharge pipe so as to Withdraw the rods 50 (FIG. 17). The sand is packed or compressed by means of the upper part 20 of the core-box (FIG. 17).

' Although specific embodiments of the invention have been described, many modifications and changes may be made therein without departing from the scope of the invention as defined in the appended claims.

The core could be provided with a plurality of reinforcements. The core-box could be arranged to produce a plurality of cores.

Having now described my invention What I claim as new and desire to secure by Letters Patent is:

1. Process of producing a foundry core which has at least one reinforcement comprising the steps of placing the reinforcement in the core-box on top of support means combined with the core-box-but movable relative to the latter, filling the core-box with the sand intended to constitute the core, moving said support means relative to the core-box and from under the reinforcement Without removing the reinforcement from the core-box and thereafter compressing said sand in the core-box.

2. Device for producing a foundry core having at least one reinforcement, said device comprising a core-box, support elements on top of which the reinforcement is placed and supported and which are carried by the corebox and are movable between a reinforcement supporting position and a retracted position in which latter posi tion the support elements are Withdrawn from under the reinforcement, springs co-operating with the support elements for urging the latter to said retracted position, and locking elements movably mounted in the core-box and engageable with the support elements in said supporting position thereof for locking the support elements in said supporting position in opposition to the action of the springs, and means for shifting the locking elements between a retracted position in which they are disengaged from the support elements and a position in Which they engage and lock the support elements.

References Cited in the file of this patent UNITED STATES PATENTS r 

1. PROCESS OF PRODUCING A FOUNDRY CORE WHICH HAS AT LEAST ONE REINFORCEMENT COMPRISING THE STEPS OF PLACING THE REINFORCEMENT IN THE CORE-BOX ON TOP OF SUPPORT MEANS COMBINED WITH THE CORE-BOX BUT MOVABLE RELATIVE TO THE LATTER, FILLING THE CORE-BOX WITH THE SAND INTENDED TO CONSTITUTE THE CORE, MOVING SAID SUPPORT MEANS RELATIVE TO THE CORE-BOX AND FROM UNDER THE REINFORCEMENT WITHOUT REMOVING THE REINFORCEMENT FROM THE CORE-BOX AND THEREAFTER COMPRESSING SAID SAND IN THE CORE-BOX. 